Drugs and poisons from a variety of sources have been used illegally for centuries and have an unfortunate, enduring fascination. People appear to be both attracted to them and at the same time repelled by them. Forensic medical scientist and toxicologist Dr William J. Allender is only too aware that all drugs, whether legal or illicit, can have adverse side-effects if misused, when inappropriate large doses are taken, or when they are mixed with other drugs or alcohol. Dr Allender has lent his expertise to solving some of Australia’s most publicised crimes over more than three decades, along the way developing a fascination with how toxic substances may have contributed to a person’s death. As a forensic toxicologist, he has been called on to give expert witness evidence in numerous cases involving the misuse of drugs whether by misadventure, deliberate overdosing, plain stupidity or, even worse, murder. In this final instalment in his popular Expert Witness series, Dr Allender is back with a further selection of case stories where the use or misuse of a toxic substance has contributed to someone’s death.